Resin composition and melt bag

ABSTRACT

Melt bags of the invention are molten uniformly at temperatures lower than melting operation temperatures in the product manufacturing and do not remain unmolten in the final products. The melt bags have high storage stability and excellent mechanical properties. Resin compositions of the invention are suited to give such melt bags. 
     A resin composition of the invention includes a propylene/C2-20 α-olefin (except propylene) copolymer (A) having (1) a melting point (Tm) of not more than 90° C. as measured by differential scanning calorimetry (DSC) or not showing a melting point peak in DSC, and an ethylene/C3-20 α-olefin copolymer (B) having (1) a melting point (Tm) of not more than 90° C. as measured by differential scanning calorimetry (DSC) or not showing a melting point peak in DSC, the weight ratio of these copolymers (A)/(B) being in the range of 99/1 to 1/99.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 12/935,578, filed Sep. 29, 2010, which is a U.S. national stageapplication claiming the benefit of International Patent Application No.PCT/JP2009/055808, filed Mar. 24, 2009, which claims the benefit ofpriority to Japanese Patent Application No. 2008-092738, filed Mar. 31,2008, the entireties of which are all hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to resin compositions comprising aspecific propylene/C2-20 α-olefin (except propylene) copolymer and aspecific ethylene/C3-20 α-olefin copolymer, melt bags formed using theresin composition, and packages containing the melt bag.

BACKGROUND OF THE INVENTION

When traffic paints for road signs, hot-melt adhesives and rubbermodifiers such as carbon blacks are mixed with other materials, they areoften supplied and molten in a Bunbury mixer or a melting furnace in theform of packages in films or bags.

Melt bags are a type of packaging bags which are molten along withcontents in the processing of the contents into products or in the useof the products, and are uniformly dispersed in the products. The use ofmelt bags is expected to provide benefits such as improved disposalproblems with used bags, a cleaner environment in taking the contentsout of the bags, higher workability and easier weighing.

Materials for the melt bags include ethylene/acrylate copolymers (EEA),ethylene/methacrylate copolymers, ethylene/vinyl acetate copolymers(EVA), resins obtained by compounding these copolymers with a smallamount of polyethylene, and ethylene/α-olefin copolymers (for example,Patent Documents 1 to 4).

However, the melt bags formed of these materials cannot be moltenuniformly at below melting operation temperatures and remain unmolten inthe final products, deteriorating the appearance and properties.Further, these melt bags are still unsatisfactory in storage stabilitywhen filled with contents or in mechanical properties of the melt bags.

-   Patent Document 1: JP-A-2005-219818-   Patent Document 2: JP-A-2005-170428-   Patent Document 3: JP-A-2004-2581-   Patent Document 4: JP-A-2000-355359

SUMMARY OF THE INVENTION

The present invention is aimed at solving the problems in the art asdescribed above. It is therefore an object of the invention to providefilms which are molten uniformly at below melting operation temperaturesand do not remain unmolten in the final products and which have highstorage stability and excellent mechanical properties. It is anotherobject to provide melt bags formed of the films, resin compositionssuited for the production of packages containing the melt bags, and meltbags formed using the resin compositions.

The present inventors studied diligently to solve the problems asdescribed above. They have then developed films which are formed of aresin composition including a specific propylene/C2-20 α-olefin (exceptpropylene) copolymer and a specific ethylene/C3-20 α-olefin copolymer.The inventors have found that the films and melt bags formed of thefilms are molten uniformly at low temperatures, do not remain unmoltenin the final products, and are excellent in storage stability andmechanical properties. The present invention has been completed based onthe findings.

The present invention is concerned with the following [1] to [14].

[1] A resin composition according to the present invention comprises apropylene/C2-20 α-olefin (except propylene) copolymer (A) having (1) amelting point (Tm) of not more than 90° C. as measured by differentialscanning calorimetry (DSC) or not showing a melting point peak in DSC,and an ethylene/C3-20 α-olefin copolymer (B) having (1) a melting point(Tm) of not more than 90° C. as measured by differential scanningcalorimetry (DSC) or not showing a melting point peak in DSC, the weightratio of these copolymers (A)/(B) being in the range of 99/1 to 1/99.

[2] In a preferred embodiment of the resin composition, thepropylene/C2-20 α-olefin (except propylene) copolymer (A) contains (2)structural units derived from propylene in an amount of 51 to 95 mol %and structural units derived from the C2-20 α-olefin (except propylene)in an amount of 5 to 49 mol %, and the ethylene/C3-20 α-olefin copolymer(B) contains (2) structural units derived from ethylene in an amount of50 to 95 mol % and structural units derived from the C3-20 α-olefin inan amount of 5 to 50 mol %.

[3] In a preferred embodiment, the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) has (3) a molecular weight distribution (Mw/Mn)of not more than 3.0 as measured by gel permeation chromatography (GPC).

[4] In a preferred embodiment, the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) is propylene/1-butene copolymer.

[5] In a preferred embodiment, the ethylene/C3-20 α-olefin copolymer (B)has (3) a molecular weight distribution (Mw/Mn) of not more than 3.0 asmeasured by gel permeation chromatography (GPC).

[6] In a preferred embodiment, the ethylene/C3-20 α-olefin copolymer (B)is ethylene/1-butene copolymer.

[7] A film according to the present invention comprises the resincomposition as described above.

[8] A melt bag according to the present invention is formed using aresin composition which comprises a propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) having (1) a melting point (Tm) of not morethan 90° C. as measured by differential scanning calorimetry (DSC) ornot showing a melting point peak in DSC, and an ethylene/C3-20 α-olefincopolymer (B) having (1) a melting point (Tm) of not more than 90° C. asmeasured by differential scanning calorimetry (DSC) or not showing amelting point peak in DSC, the weight ratio of these copolymers (A)/(B)being in the range of 100/0 to 1/99.

[9] In a preferred embodiment of the melt bag, the propylene/C2-20α-olefin (except propylene) copolymer (A) contains (2) structural unitsderived from propylene in an amount of 51 to 95 mol % and structuralunits derived from the C2-20 α-olefin (except propylene) in an amount of5 to 49 mol %, and the ethylene/C3-20 α-olefin copolymer (B) contains(2) structural units derived from ethylene in an amount of 50 to 95 mol% and structural units derived from the C3-20 α-olefin in an amount of 5to 50 mol %.

[10] In a preferred embodiment of the melt bag, the propylene/C2-20α-olefin (except propylene) copolymer (A) has (3) a molecular weightdistribution (Mw/Mn) of not more than 3.0 as measured by gel permeationchromatography (GPC).

[11] In a preferred embodiment of the melt bag, the propylene/C2-20α-olefin (except propylene) copolymer (A) is propylene/1-butenecopolymer.

[12] In a preferred embodiment of the melt bag, the ethylene/C3-20α-olefin copolymer (B) has (3) a molecular weight distribution (Mw/Mn)of not more than 3.0 as measured by gel permeation chromatography (GPC).

[13] In a preferred embodiment of the melt bag, the ethylene/C3-20α-olefin copolymer (B) is ethylene/1-butene copolymer.

[14] A package according to the present invention includes the melt bagas described above.

Advantageous Effects of the Invention

The resin compositions of the invention are molten uniformly attemperatures lower than melting operation temperatures in the productmanufacturing and do not remain unmolten in the final products, and areexcellent in storage stability and mechanical properties. Thecompositions are therefore suitably used to produce films, melt bags andpackages. The melt bags of the invention allow for favorablepreservation of contents, and are molten uniformly at low temperaturesand do not remain unmolten in the final products.

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

The present invention will be described in detail below.

A resin composition according to the present invention includes aspecific propylene/C2-20 α-olefin (except propylene) copolymer (A) and aspecific ethylene/C3-20 α-olefin copolymer (B).

A melt bag according to the invention is formed using a resincomposition that includes a specific propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) and a specific ethylene/C3-20 α-olefincopolymer (B).

<Propylene/C2-20 α-Olefin (Except Propylene) Copolymers (A)>

The propylene/C2-20 α-olefin (except propylene) copolymers (A) satisfythe melting point (Tm) (1) described below, and preferably satisfy therequirement (2) described below. More preferably, the copolymers satisfythe requirement (3) described below in addition to the requirement (1)or the requirements (1) and (2). Still more preferably, the copolymerssatisfy at least one of the requirements (4) and (5) described below inaddition to any of the requirement (1), the requirements (1) and (2),the requirements (1) and (3), and the requirements (1), (2) and (3). Inthe most preferred embodiment, the copolymers satisfy all therequirements (1) to (6) described below.

(1) The copolymers have a melting point (Tm) of not more than 90° C. asmeasured by differential scanning calorimetry (DSC) or do not show amelting point peak in DSC. In a preferred embodiment, the melting point(Tm) is in the range of 40 to 85° C., more preferably 45 to 85° C., andstill more preferably 50 to 80° C. If the melting point is below 40° C.,the obtainable composition will have tackiness at room temperature andis likely to cause problems such as blocking. If the melting pointexceeds 90° C., the obtainable composition will remain unmolten in thefinal products.

(2) The copolymers contain structural units derived from propylene in anamount of 51 to 95 mol %, preferably 55 to 90 mol %, more preferably 60to 80 mol %, and structural units derived from the C2-20 α-olefin(except propylene) in an amount of 5 to 49 mol %, preferably 10 to 45mol %, more preferably 20 to 40 mol %. This propylene content ensuresthat the obtainable melt bags do not remain unmolten in the finalproducts and that tackiness is not caused around room temperature andproblems such as blocking of the melt bags are prevented.

The propylene/C2-20 α-olefin (except propylene) copolymers (A) maycontain structural units derived from propylene and structural unitsderived from a plurality of C2-20 α-olefins (except propylene). TheC2-20 α-olefins (except propylene) include ethylene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene,1-hexadecene and 4-methyl-1-pentene. A preferred structural unit derivedfrom the C2-20 α-olefin (except propylene) is 1-butene.

(3) The copolymers have a molecular weight distribution (Mw/Mn) of notmore than 3.0, preferably in the range of 1.5 to 2.8, and morepreferably 1.7 to 2.5 as measured by gel permeation chromatography(GPC). The molecular weight distribution (Mw/Mn) in this range ensuresthat blocking due to low-molecular weight components or unmoltenhigh-molecular weight component residues are reduced.

(4) The intrinsic viscosity [η] as measured at 135° C. in decalin is inthe range of 0.1 to 12 dl/g, preferably 0.2 to 10 dl/g, and morepreferably 0.3 to 5 dl/g.

(5) The melting point Tm as measured by differential scanningcalorimetry is not more than 90° C., preferably in the range of 40 to85° C., more preferably 45 to 85° C., and the melting point Tm and thecontent M (mol %) of structural units derived from the C2-20 α-olefin(except propylene) satisfy the following relation:

−2.6M+130≦Tm≦−2.3M+155.

(6) When the copolymer is analyzed by ¹³C-NMR spectroscopy(hexachlorobutadiene solution, tetramethylsilane standard) with respectto the side-chain methyl group in the propylene unit that is the secondunit in (i) head-to-tail coupled propylene unit triad sequences or (ii)propylene/C2-20 α-olefin (except propylene) triad sequences composed ofhead-to-tail coupled propylene unit(s) and C2-20 α-olefin (exceptpropylene) unit(s) and having the propylene unit as the second unit, theareas of peaks observed at 21.0 to 21.9 ppm (triad tacticity) representnot less than 90%, preferably not less than 92%, and more preferably notless than 94% of the total of areas at 19.5 to 21.9 ppm as 100%. Thetriad tacticity in this range ensures that problems such as blocking arenot caused.

The stereoregularity of the propylene/C2-20 α-olefin (except propylene)copolymers (A) may be evaluated based on the triad tacticity (mmfraction).

In propylene/butene-1 random copolymer as an example, the mm fraction isdefined as a proportion of triad sequences that have the methyl groupsbranched in the same direction, relative to all the triad sequences inthe polymer chain that are head-to-tail coupled to show a zigzagstructure. The mm fraction is determined from a ¹³C-NMR spectrum asdescribed below.

In the determination of the mm fraction from a ¹³C-NMR spectrum, thepolymer chains are analyzed to determine the mm fraction of triadsequences containing a propylene unit(s), in detail (i) head-to-tailcoupled propylene unit triad sequences and (ii) propylene unit/butene-1unit triad sequences that are composed of head-to-tail coupled propyleneunit(s) and butene-1 unit(s) and have the propylene unit as the secondunit.

The mm fraction is obtained from peak intensities assigned to theside-chain methyl groups in the second units (propylene units) of thetriad sequences (i) and (ii).

The propylene/C2-20 α-olefin (except propylene) copolymers (A) usuallyhave a melt flow rate MFR (ASTM D1238, 230° C., 2.16 kg load) in therange of 0.5 to 20 g/10 min, and preferably 1 to 10 g/10 min.

A detailed description is given below.

To obtain a ¹³C-NMR spectrum of the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A), the propylene/C2-20 α-olefin (exceptpropylene) copolymer is completely dissolved in a lock solventconsisting of hexachlorobutadiene and a small amount of deuteratedbenzene in a sample tube, and the resultant sample is analyzed bycomplete proton decoupling at 120° C. Measurement conditions are suchthat the flip angle is 45° and the pulse intervals are at least 3.4T₁(T₁ is the longest spin-lattice relaxation time of the methyl group).The methylene and methine groups have shorter T₁ than that of the methylgroup, and therefore all the carbon atoms in the sample will have amagnetization recovery rate of 99% or more under the above conditions.The chemical shifts are determined based on tetramethylsilane as thereference compound, and the peak assigned to the methyl group carbon ofthe third unit in head-to-tail coupled propylene unit pentad sequences(mmmm) is determined to be 21.593 ppm and other carbon peaks aredetermined based on this peak.

With respect to the ¹³C-NMR spectrum of the propylene/C2-20 α-olefin(except propylene) copolymer recorded as above, the regions havingmethyl carbon peaks assigned to the side-chain methyl groups of thepropylene units (approximately 19.5 to 21.9 ppm) are divided into thefirst peak region (approximately 21.0 to 21.9 ppm), the second peakregion (approximately 20.2 to 21.0 ppm) and the third peak region(approximately 19.5 to 20.2 ppm).

In these peak regions, the carbons in the side-chain methyl groups inthe second units (propylene units) of the head-to-tail coupled triadsequences (i) and (ii) give peaks as shown in Table 1.

TABLE 1 Methyl carbon regions (19.5-21.9 ppm) First Second Third regionregion region 21.0-21.9 20.2-21.0 19.5-20.2 Shifts ppm ppm ppm SequencePPP (mm) PPP (mr) PPP (rr) (i) Head- Sequence PPB (mm) PPB (mr) to-tail(ii) BPB (mm) BPB (mr) coupled PPB (rr) BPB (rr)

In Table 1, P denotes a unit derived from propylene, and B denotes aunit derived from the C2-20 α-olefin (except propylene) such as butene.

Of the head-to-tail coupled triad sequences (i) and (ii) given in Table1, the triad sequences (i) PPP (mm), PPP (mr) and PPP (rr) consisting ofthree propylene units are illustrated below in zigzag structuresreflecting the branching direction of the methyl groups. Theseillustrations of mm, mr and rr couplings in PPP also apply to the triadsequences (ii) (PPB and BPB) that contain C2-20 α-olefin (exceptpropylene) unit(s).

In the first region, the methyl groups in the second units (propyleneunits) of the mm-coupled triad sequences PPP, PPB and BPB give resonancepeaks.

The second region shows resonance peaks of the methyl groups in thesecond units (propylene units) of the mr-coupled triad sequences PPP,PPB and BPB, and resonance peaks assigned to the methyl groups in thesecond units (propylene units) of the rr-coupled triad sequences PPB andBPB.

In the third region, the methyl groups in the second units (propyleneunits) of the rr-coupled triad sequences PPP give a resonance peaks.

Accordingly, the triad tacticity (mm fraction) of the propyleneelastomer is a proportion (percentage) of the area of the peaks observedin the range of 21.0 to 21.9 ppm (the first region) relative to thetotal (100%) of the areas of the peaks found within 19.5 to 21.9 ppm(the methyl carbon regions) according to measurement by ¹³C-NMRspectroscopy (hexachlorobutadiene solution, tetramethylsilane standard)based on the side-chain methyl groups in the second propylene units of(i) the head-to-tail coupled propylene unit triad sequences or (ii) thepropylene/C2-20 α-olefin (except propylene) triad sequences composed ofhead-to-tail coupled propylene unit(s) and C2-20 α-olefin (exceptpropylene) unit(s) and having the propylene unit as the second unit.Specifically, the mm fraction may be obtained from the followingequation:

$\begin{matrix}{\mspace{79mu} \left\lbrack {{Formula}\mspace{14mu} 1} \right\rbrack} & \; \\{{m\; m\mspace{14mu} {fraction}\mspace{14mu} (\%)} = {\frac{\begin{matrix}{{Intensities}\mspace{14mu} {of}\mspace{14mu} {methyl}\mspace{14mu} {groups}} \\\left\lbrack {{{PPP}\mspace{11mu} \left( {m\; m} \right)} + {{PPB}\mspace{11mu} \left( {m\; m} \right)} + {{BPB}\mspace{14mu} \left( {m\; m} \right)}} \right\rbrack\end{matrix}}{\begin{matrix}{{Intensities}\mspace{14mu} {of}\mspace{14mu} {methyl}\mspace{14mu} {groups}} \\\begin{bmatrix}{{{PPP}\mspace{14mu} \left( {m\; m} \right)} + {{PPB}\mspace{14mu} \left( {m\; m} \right)} + {{BPB}\mspace{14mu} \left( {m\; m} \right)} +} \\{{{PPP}\mspace{14mu} ({mr})} + {{PPB}\mspace{14mu} ({mr})} + {{BPB}\mspace{14mu} ({mr})} +} \\{{{PPP}\mspace{14mu} ({rr})} + {{PPB}\mspace{11mu} ({rr})} + {{BPB}\mspace{14mu} ({rr})}}\end{bmatrix}\end{matrix}} \times 100}} & (1)\end{matrix}$

The mm fraction of the propylene/C2-20 α-olefin (except propylene)copolymer (A) is 90% or more, preferably 92% or more, and morepreferably 94% or more.

The propylene elastomer contains, in addition to the head-to-tailcoupled triad sequences (i) and (ii), small amounts of structural unitsthat include irregularly arranged units as illustrated in the structures(iii), (iv) and (v). The side-chain methyl groups in these otherwisecoupled propylene units also show peaks within the above methyl carbonregions (19.5 to 21.9 ppm).

In the methyl groups in these structures (iii), (iv) and (v), the methylgroup carbons A and B give resonance peaks at 17.3 ppm and 17.0 ppmrespectively, outside the first to third regions (19.5 to 21.9 ppm).Since the carbons A and B are not involved in the formation ofhead-to-tail coupled propylene triad sequences, the peaks thereof shouldbe neglected in the calculation of the triad tacticity (mm fraction).

Meanwhile, the peaks assigned to the methyl group carbons C, D and D′appear in the second region, and those assigned to the methyl groupcarbons E and E′ are found in the third region.

Therefore, the first to third methyl carbon regions show the peaksassigned to the PPE-methyl groups (the side-chain methyl groups inpropylene-propylene-ethylene sequences) (near 20.7 ppm), the EPE-methylgroups (the side-chain methyl groups in ethylene-propylene-ethylenesequences) (near 19.8 ppm), the methyl groups C, the methyl groups D,the methyl groups D′, the methyl groups E and the methyl groups E′.

As described above, the methyl carbon regions show peaks assigned to themethyl groups in sequences other than the head-to-tail coupled triadsequences (i) and (ii). These peaks are corrected as described below inthe determination of the mm fraction from the above formula.

The peak area of the PPE-methyl groups can be obtained from the peakarea of the PPE-methine groups (resonating near 30.6 ppm). The peak areaof the EPE-methyl groups can be obtained from the peak area of theEPE-methine groups (resonating near 32.9 ppm). The peak area of themethyl groups C can be obtained from the peak area of the adjacentmethine groups (resonating near 31.3 ppm). The peak area of the methylgroups D is half the combined peak areas of α and β methylene carbons inthe structure (iv) (resonating near 34.3 ppm and near 34.5 ppm). Thepeak area of the methyl groups D′ can be obtained from the peak area ofthe methine groups (resonating near 33.3 ppm) adjacent to the methylgroups E′ in the structure (v). The peak area of the methyl groups E canbe obtained from the peak area of the adjacent methine carbons(resonating near 33.7 ppm). The peak area of the methyl groups E′ can beobtained from the peak area of the adjacent methine carbons (resonatingnear 33.3 ppm).

Accordingly, subtracting these peak areas from the total peak areas inthe second and third regions gives an area of the peaks assigned to themethyl groups in the head-to-tail coupled propylene unit triad sequences(i) and (ii).

The mm fraction is calculated according to the above-described formulabased on the peak area of the methyl groups in the head-to-tail coupledpropylene unit triad sequences (i) and (ii) provided by the abovesubtraction. The carbon peaks found in the spectrum may be assigned withreference to the literature (Polymer, 30, 1350 (1989)).

The propylene/C2-20 α-olefin (except propylene) copolymers (A) may befavorably obtained by copolymerizing propylene, a C2-20 α-olefin exceptpropylene and optionally small amounts of other olefins as required inthe presence of a Ziegler-Natta catalyst or a catalyst containing ametallocene compound. The Ziegler-Natta catalysts may be produced bymethods as described in JP-A-H02-43242, JP-A-H03-66737 andJP-A-H06-263935. The catalysts containing a metallocene compound may beprepared by methods as disclosed in WO 2004/087775 and WO 01/27124.

In more detail, the propylene/C2-20 α-olefin (except propylene)copolymers (A) may be produced by copolymerizing propylene and a C2-20α-olefin (except propylene), preferably by copolymerizing propylene and1-butene as the α-olefin, in the presence of a Ziegler-Natta catalystwhich contains (a) a complex containing at least magnesium, titanium andhalogen, (b) an organometallic compound having a metal of Group 1 toGroup 3 of the periodic table, and (c) an electron donor. Part or wholeof the electron donor (c) may be immobilized on part or whole of thecomplex (a) or may be brought into contact with the organometalliccompound (b) before use. In a particularly preferred embodiment, part ofthe electron donor (c) is immobilized on the complex (a) and theremaining part of the electron donor is supplied to the polymerizationsystem directly or after preliminarily contacted with the organometalliccompound (b). In this embodiment, the electron donor immobilized on thecomplex (a) and the electron donor that is directly supplied to thepolymerization system or preliminarily contacted with the organometalliccompound (b) may be the same or different from each other.

In a preferred embodiment, the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) is produced by copolymerizing propylene and aC2-20 α-olefin (except propylene) in the presence of a metallocenecatalyst that contains a transition metal compound (1a) represented byFormula (1a) below. Herein, the catalyst containing the transition metalcompound (1a) preferably contains together with the transition metalcompound (1a) at least one compound selected from (2a) organometalliccompounds, (2b) organoaluminum oxy-compounds and (2c) compounds capableof reacting with the trans it ion metal compound (1a) to form an ionpair.

In Formula (1a), R¹ and R³ are each a hydrogen atom; R² and R⁴ are eachselected from hydrocarbon groups and silicon-containing groups and maybe the same or different from each other; R⁵, R⁶, R⁷, R⁹, R⁹, R¹⁰, R¹¹,R¹², R¹³ and R¹⁴ are each selected from hydrogen atom, hydrocarbongroups and silicon-containing groups and may be the same or differentfrom one another; adjacent substituent groups of R⁵ to R¹² may be linkedwith each other to form a ring; R¹³ and R¹⁴ are the same or differentfrom each other and may be linked together to form a ring; M is a Group4 transition metal; Y is a carbon atom; Q is a halogen, a hydrocarbongroup, an anionic ligand or a neutral ligand capable of coordination viaa lone pair of electrons, and may be the same or different when plural;and j is an integer ranging from 1 to 4.

The hydrocarbon groups include linear hydrocarbon groups such as methyl,ethyl, n-propyl, allyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl,n-nonyl and n-decanyl groups; branched hydrocarbon groups such asisopropyl, tert-butyl, amyl, 3-methylpentyl, 1,1-diethylpropyl,1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl,1,1-dimethyl-2-methylpropyl and 1-methyl-1-isopropyl-2-methylpropylgroups; saturated cyclic hydrocarbon groups such as cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl, norbornyl and adamantyl groups;unsaturated cyclic hydrocarbon groups such as phenyl, tolyl, naphthyl,biphenyl, phenanthryl and anthracenyl groups; saturated hydrocarbongroups substituted with unsaturated cyclic hydrocarbon groups, such asbenzyl, cumyl, 1,1-diphenylethyl and triphenylmethyl groups; andheteroatom-containing hydrocarbon groups such as methoxy, ethoxy,phenoxy, furyl, N-methylamino, N,N-dimethylamino, N-phenylamino, pyrryland thienyl groups.

The silicon-containing groups include trimethylsilyl, triethylsilyl,dimethylphenylsilyl, diphenylmethylsilyl and triphenylsilyl groups.Adjacent substituent groups of R⁵ to R¹² may link together to form aring. Examples of such substituted fluorenyl groups includebenzofluorenyl, dibenzofluorenyl, octahydrodibenzofluorenyl,octamethyloctahydrodibenzofluorenyl andoctamethyltetrahydrodicyclopentafluorenyl groups.

In Formula (1a), R² and R⁴ on the cyclopentadienyl ring are preferablyC1-20 hydrocarbon groups. Examples of the C1-20 hydrocarbon groupsinclude the aforementioned hydrocarbon groups. More preferably, R² is abulky substituent group such as tert-butyl, adamantyl or triphenylmethylgroup, and R⁴ is a dimensionally smaller substituent group than R², suchas methyl, ethyl or n-propyl group. As used herein, the words“dimensionally smaller” mean that the substituent group has a smallervolume.

Of the substituent groups R⁵ to R¹² on the fluorene ring in Formula(1a), arbitrary two or more groups of R⁶, R⁷, R¹⁰ and R¹¹ are preferablyC1-20 hydrocarbon groups. Examples of the C1-20 hydrocarbon groupsinclude the aforesaid hydrocarbon groups. For the purpose of easysynthesis of the ligand, these groups are preferably symmetrical, indetail R⁶ and R¹¹ are the same groups and R⁷ and R¹⁰ are the samegroups. In one of such preferred embodiments, R⁶ and R⁷ form analiphatic ring (AR-1) and R¹⁰ and R¹¹ form an aliphatic ring (AR-2)identical to the aliphatic ring (AR-1).

Referring to Formula (1a), Y which bridges the cyclopentadienyl ring andthe fluorenyl ring is a carbon atom. The substituent groups R¹³ and R¹⁴bonded to Y are preferably both aryl groups having 6 to 20 carbon atoms.These substituent groups may be the same or different from each otherand may link together to form a ring. Exemplary C6-20 aryl groupsinclude the above-mentioned unsaturated cyclic hydrocarbon groups,saturated hydrocarbon groups substituted with unsaturated cyclichydrocarbon groups, and heteroatom-containing unsaturated cyclichydrocarbon groups. R¹³ and R¹⁴ may be the same or different from eachother and may link together to form a ring. Preferred examples of suchsubstituent groups include fluorenylidene, 10-hydroanthracenylidene anddibenzocycloheptadienylidene groups.

In Formula (1a), M denotes a Group 4 transition metal such as Ti, Zr orHf; Q denotes a halogen atom, a hydrocarbon group, an anionic ligand ora neutral ligand capable of coordination via a lone pair of electrons,and may be the same or different when plural; and j is an integer of 1to 4. When j is 2 or greater, the plurality of Q may be the same ordifferent. The halogens include fluorine, chlorine, bromine and iodine.Examples of the hydrocarbon groups are as described above. Exemplaryanionic ligands include alkoxy groups such as methoxy, tert-butoxy andphenoxy groups; carboxylate groups such as acetate and benzoate groups;and sulfonate groups such as mesylate and tosylate groups. The neutralligands capable of coordination via a lone pair of electrons includeorganophosphorus compounds such as trimethylphosphine,triethylphosphine, triphenylphosphine and diphenylmethylphosphine; andethers such as tetrahydrofuran, diethyl ether, dioxane and1,2-dimethoxyethane. In a preferred embodiment, at least one Q is ahalogen atom or an alkyl group.

Examples of the transition metal compounds (1a) include but are notlimited to isopropylidene(3-tert-butyl-5-methylcyclopentadienyl)(fluorenyl) zirconium dichloride,isopropylidene (3-tert-butyl-5-methylcyclopentadienyl)(2,7-di-tert-butylfluorenyl)zirconium dichloride,isopropylidene(3-tert-butyl-5-methylcyclopentadienyl)(3,6-di-tert-butylfluorenyl)zirconium dichloride,isopropylidene(3-tert-butyl-5-methylcyclopentadienyl)(octamethyloctahydridodibenzofluorenyl)zirconium dichloride,diphenylmethylene(3-tert-butyl-5-methylcyclopentadienyl)(fluorenyl)zirconium dichloride, diphenylmethylene(3-tert-butyl-5-methylcyclopentadienyl)(2,7-di-tert-butylfluorenyl)zirconium dichloride,diphenylmethylene(3-tert-butyl-5-methylcyclopentadienyl)(3,6-di-tert-butylfluorenyl)zirconium dichloride anddiphenylmethylene(3-tert-butyl-5-methylcyclopentadienyl)(octamethyloctahydridodibenzofluorenyl)zirconium dichloride.

The catalysts that are suitably used in the production of thepropylene/C2-20 α-olefin (except propylene) copolymers (A) contain,together with the transition metal compound (1a) described above, atleast one compound selected from (2a) organometallic compounds, (2b)organoaluminum oxy-compounds and (2c) compounds capable of reacting withthe trans it ion metal compound (1a) to form an ion pair. Thesecompounds (2a), (2b) and (2c) are not particularly limited. Preferredcompounds include those described in WO 2004/087775 and WO 01/27124.Exemplary compounds are described below.

The organometallic compounds (2a) for use in the invention includeorganic compounds of Group 1, 2, 12 and 13 metals as follows.

(2a-1) Organoaluminum compounds represented by:

R^(a) _(m)Al(OR^(b))_(n)H_(p)X_(q)

wherein R^(a) and R^(b) may be the same or different from each other andare each a hydrocarbon group of 1 to 15, and preferably 1 to 4 carbonatoms, X is a halogen atom, 0<m≦3, 0≦n<3, 0≦p<3, 0≦q<3 and m+n+p+q=3.Specific examples of such compounds include trimethylaluminum,triethylaluminum, triisobutylaluminum and diisobutylaluminum hydride.

(2a-2) Alkyl complex compounds of Group 1 metal and aluminum,represented by:

M²AlR^(a) ₄

wherein M² is Li, Na or K, and R^(a) is a hydrocarbon group of 1 to 15,and preferably 1 to 4 carbon atoms. Specific examples of such compoundsinclude LiAl(C₂H₅)₄ and LiAl(C₇H₁₅)₄.

(2a-3) Dialkyl compounds of Group 2 or 12 metal, represented by:

R^(a)R^(b)M³

wherein R^(a) and R^(b) may be the same or different from each other andare each a hydrocarbon group of 1 to 15, and preferably 1 to 4 carbonatoms, and M³ is Mg, Zn or Cd.

Of the above organometallic compounds (2a), the organoaluminum compoundsare preferred. The organometallic compounds (2a) may be used singly, ortwo or more kinds may be used in combination.

The organoaluminum oxy-compounds (2b) may be conventional aluminoxanes,or benzene-insoluble organoaluminum oxy-compounds as disclosed inJP-A-H02-78687.

For example, the conventional aluminoxanes may be prepared by thefollowing processes, and are usually obtained as a solution in ahydrocarbon solvent.

(1) An organoaluminum compound such as trialkylaluminum is added to ahydrocarbon medium suspension of a compound containing adsorbed water ora salt containing water of crystallization (such as magnesium chloridehydrate, copper sulfate hydrate, aluminum sulfate hydrate, nickelsulfate hydrate or cerous chloride hydrate), to react the organoaluminumcompound with the adsorbed water or the water of crystallization.

(2) Water, ice or water vapor is allowed to act directly on anorganoaluminum compound such as trialkylaluminum in a medium such asbenzene, toluene, diethyl ether or tetrahydrofuran.

(3) An organoaluminum compound such as trialkylaluminum is reacted withan organotin oxide such as dimethyltin oxide or dibutyltin oxide in amedium such as decane, benzene or toluene.

The aluminoxane may contain small amounts of organometallic components.After the solvent and unreacted organoaluminum compound are distilledaway from the recovered solution of the aluminoxane, the residue may beredissolved in a solvent or suspended in a poor solvent for thealuminoxane. Examples of the organoaluminum compounds used in preparingthe aluminoxanes include the organoaluminum compounds mentioned above asthe organoaluminum compounds (2a-1). Of those compounds,trialkylaluminums and tricycloalkylaluminums are preferred, andtrimethylaluminum is particularly preferred. The organoaluminumcompounds may be used singly, or two or more kinds may be used incombination.

The benzene-insoluble organoaluminum oxy-compounds desirably contain Alcomponents that will dissolve in benzene at 60° C. in an amount of 10%or less, preferably 5% or less, and particularly preferably 2% or lessin terms of Al atoms. That is, the organoaluminum oxy-compounds arepreferably insoluble or hardly soluble in benzene. The organoaluminumoxy-compounds (2b) may be used singly, or two or more kinds may be usedin combination.

The compounds (2c) capable of reacting with the transition metalcompound (1a) to form an ion pair include Lewis acids, ionic compounds,borane compounds and carborane compounds as disclosed inJP-A-H01-501950, JP-A-H01-502036, JP-A-H03-179005, JP-A-H03-179006,JP-A-H03-207703, JP-A-H03-207704 and U.S. Pat. No. 5,321,106. Further,heteropoly compounds and isopoly compounds are also usable. Thecompounds (2c) may be used singly, or two or more kinds may be used incombination.

In the production of the propylene/C2-20 α-olefin (except propylene)copolymers (A), particularly high polymerization activity is achievedwhen the catalyst contains the transition metal compound (1a) and theorganoaluminum oxy-compound (2b) such as methylaluminoxane.

The polymerization catalysts for the production of the propylene/C2-20α-olefin (except propylene) copolymers (A) may contain a carrier or acocatalyst component as required.

Such catalysts may be prepared by mixing the components directly orafter the components are supported on carriers. Alternatively, thecomponents for the catalyst may be added to the polymerization systemsimultaneously or successively.

In a preferred embodiment, the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) is produced by copolymerizing propylene and aC2-20 α-olefin (except propylene) which is particularly preferablybutene, and optionally small amounts of other olefins in the presence ofthe aforementioned catalyst. In the copolymerization, the monomers maybe used in amounts such that the desired ratio of structural units inthe obtainable propylene/C2-20 α-olefin (except propylene) copolymer (A)is achieved. In detail, the monomers are desirably used in apropylene/C2-20 α-olefin (except propylene) molar ratio of 50/50 to95/5, preferably 60/40 to 93/7, and more preferably 70/30 to 90/10.

The copolymerization conditions are not particularly limited. Forexample, the polymerization temperature may be usually in the range of−50 to +200° C., preferably 0 to 170° C., and the polymerizationpressure may generally range from atmospheric pressure to 10 MPaG,preferably from atmospheric pressure to 5 MPaG. The polymerizationreaction may be carried out batchwise, semi-continuously orcontinuously. In an embodiment, the polymerization may be performed intwo or more stages under different reaction conditions. The molecularweight of the propylene/C2-20 α-olefin (except propylene) copolymer (A)may be controlled by the presence of hydrogen in the polymerizationsystem or by changing the polymerization temperature. The molecularweight is also controllable by adjusting the amount of the compound(2a), (2b) or (2c) in the catalyst. When hydrogen is used, the amountthereof may be suitably in the range of about 0.001 to 100 NL per 1 kgof the monomers.

(Ethylene/C3-20 α-olefin copolymers (B)) The ethylene/C3-20 α-olefincopolymers (B) may be conventional copolymers as long as they satisfythe melting point (Tm) requirement (1) described below. Preferably, thecopolymers further satisfy the requirement (2) described below. Morepreferably, the copolymers satisfy the requirement (3) described belowin addition to the requirement (1) or the requirements (1) and (2). Inan optimum embodiment, the copolymers satisfy all the requirements (1)to (4) described below.

(1) The copolymers have a melting point (Tm) of not more than 90° C. asmeasured by differential scanning calorimetry (DSC) or do not show amelting point peak in DSC. In a preferred embodiment, the melting point(Tm) is in the range of 40 to 85° C., more preferably 45 to 85° C., andstill more preferably 50 to 80° C.

(2) The copolymers contain structural units derived from ethylene in anamount of 50 to 95 mol %, preferably 60 to 90 mol %, and structuralunits derived from the C3-20 α-olefin in an amount of 5 to 50 mol %,preferably 10 to 40 mol %. These contents ensure that the obtainablemelt bags will not remain unmolten in the final products and thattackiness is not caused around room temperature and problems such asblocking of the melt bags are reduced.

The ethylene/C3-20 α-olefin copolymers (B) may contain structural unitsderived from ethylene and structural units derived from a plurality ofC3-20 α-olefins. The C3-20 α-olefins include propylene, 1-butene,1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene,1-hexadecene and 4-methyl-1-pentene. Preferred structural units derivedfrom the C3-20 α-olefin are propylene and 1-butene, and particularlypreferably 1-butene.

(3) The copolymers have a molecular weight distribution (Mw/Mn) of notmore than 3.0, preferably in the range of 1.5 to 2.8, and morepreferably 1.7 to 2.5 as measured by gel permeation chromatography(GPC). The molecular weight distribution (Mw/Mn) in this range ensuresthat blocking due to low-molecular weight components or unmoltenhigh-molecular weight component residues are reduced.

(4) The intrinsic viscosity [η] as measured at 135° C. in decalin is inthe range of 0.1 to 12 dl/g, preferably 0.2 to 10 dl/g, and morepreferably 0.3 to 5 dl/g.

The ethylene/C3-20 α-olefin copolymers (B) usually have a melt flow rateMFR (ASTM D1238, 190° C., 2.16 kg load) in the range of 0.1 to 70 g/10min, and preferably 0.2 to 35 g/10 min.

The ethylene/C3-20 α-olefin copolymers (B) may be random copolymers orblock copolymers. In the invention, the ethylene/C3-20 α-olefincopolymers (B) are preferably random copolymers.

The ethylene/C3-20 α-olefin copolymers (B) may be produced by knownmethods using conventional solid titanium catalyst (Ziegler catalyst)components or metallocene compound catalyst components.

[Resin Compositions]

The resin compositions according to the present invention contain thepropylene/C2-20 α-olefin (except propylene) copolymer (A) and theethylene/C3-20 α-olefin copolymer (B) in a weight ratio (A)/(B) of 99/1to 1/99, and preferably 90/10 to 10/90. The resin compositions may besuitably used in films and melt bags formed of the films as will bedescribed later.

For the production of films that are particularly suited as melt bags,the resin composition contains the propylene/C2-20 α-olefin (exceptpropylene) copolymer (A) and the ethylene/C3-20 α-olefin copolymer (B)in a weight ratio (A)/(B) of 100/0 to 1/99, and preferably 90/10 to10/90.

According to a preferred embodiment, the resin composition can give meltbags having excellent rigidity and higher usability when the compositioncontains the propylene/C2-20 α-olefin (except propylene) copolymer (A)and the ethylene/C3-20 α-olefin copolymer (B) in a weight ratio (A)/(B)of 90/10 to 51/49.

According to another preferred embodiment, the resin composition cangive melt bags having excellent melting properties (molten state) at lowtemperatures when the composition contains the propylene/C2-20 α-olefin(except propylene) copolymer (A) and the ethylene/C3-20 α-olefincopolymer (B) in a weight ratio (A)/(B) of 50/50 to 10/90.

The propylene/C2-20 α-olefin (except propylene) copolymer (A) that iscontained at not less than 1 wt % in the resin composition givesrigidity to the films obtained from the resin composition.

The use of the ethylene/C3-20 α-olefin copolymer (B) in the resincomposition provides advantages that the composition has a lower meltingpoint (Tm) and good flexibility.

The resin compositions of the invention may contain additives asrequired, such as antioxidants, lubricants, heat stabilizers, UVabsorbers, anti-blocking agents, slip agents and antistatic agents. Theamount of these additives may be in the range of 0.001 to 10 parts byweight, and preferably 0.005 to 5 parts by weight based on 100 parts byweight of the copolymers (A) and (B) combined.

Known processes may be adopted to produce the resin compositionscontaining the propylene/C2-20 α-olefin (except propylene) copolymer (A)and the ethylene/C3-20 α-olefin copolymer (B). For example, thecomponents may be mixed together with a mixing apparatus such as atwin-cylinder mixer, a ribbon blender or a Henschel mixer and/or may bekneaded together by means of a kneading device such as an extruder, amixing roll, a Banbury mixer or a kneader. The resin compositionobtained by the mixing may be pelletized or granulated with an extruderor the like, or may be directly formed into a film or sheet as a resincomposition layer.

[Films]

Films according to the invention are formed from the resin compositionsas described above. The films are molten uniformly at temperatures lowerthan the melting operation temperatures in the product manufacturing,and are excellent in storage stability and mechanical properties. Thefilms are particularly suited for the production of melt bags.

Because of the excellent mechanical properties, the films of theinvention may be suitably used in applications requiring impactstrength.

The films of the invention can be sealed at low temperatures to allowfor the production of melt bags without deteriorating properties of thefilms.

The thickness of the films is not particularly limited and may bedetermined appropriately depending on applications. The thickness,however, is generally in the range of about 5 to 500 μm, preferablyabout 10 to 300 μm, and more preferably about 15 to 200 μm.

The resin compositions of the invention may be formed into any shapeswithout limitation. In a desired embodiment, the compositions are shapedinto films or sheets (hereinafter, collectively films) for theproduction of the films or the melt bags according to the invention.

The films of the resin compositions include unstretched films obtainedfrom the resin compositions by a usual T-die method or a blown-filmextrusion method, and two-layer or multilayer films having theunstretched film as a surface layer on one or both sides.

[Melt Bags]

Melt bags of the invention are produced from the inventive films byknown bag-making processes without limitation. In an exemplary process,a tubular film manufactured by a blown-film extrusion method is cut to adesired length and one of the openings is heat sealed.

The melt bags of the invention are molten uniformly at temperatureslower than melting operation temperatures in the product manufacturing,and are excellent in storage stability and mechanical properties,thereby finding wide use as melt bags.

Because the melt bags of the invention are molten uniformly attemperatures lower than melting operation temperatures in the productmanufacturing, they do not remain unmolten in the final products.

Because of the excellent storage stability and mechanical properties,the melt bags of the invention allow for preservation of contents ingood condition.

The thickness of the melt bags is variable depending on the size of themelt bags or the amount of items packed in the bags. For example, thethickness is generally in the range of about 5 to 500 μm, preferablyabout 10 to 300 μm, and more preferably about 15 to 200 μm.

[Packages]

Packages according to the invention include contents packed in the meltbags of the invention. The contents herein are materials that are heatedand molten when used, and examples thereof include polymers,compositions of polymers and compositions of these materials withvarious fillers. Specific examples are road sign materials andelastomers.

Typical road sign materials contain binder components which aretackifier resins such as rosins, aliphatic hydrocarbon resins, alicyclichydrocarbon resins, aromatic hydrocarbon resins, low-molecular vinylaromatic compound copolymers, terpene resins and modified products ofthese resins, and also contain pigments, inorganic fillers and glassbeads. The melt bags of the invention show very good compatibility withthe aforementioned elastomers and the above road sign materials.

EXAMPLES

The present invention will be described in greater detail based onexamples hereinbelow without limiting the scope of the invention.

Properties were measured or evaluated by the following methods.

[Evaluation Items] [1-Butene and Ethylene Contents]

These contents were determined by ¹³C-NMR.

[Molecular Weight Distribution]

The molecular weight distribution (Mw/Mn) was determined by GPC (gelpermeation chromatography) using gel permeation chromatograph AllianceGPC-2000 manufactured by Waters. The separatory columns used were twoTSKgel GNH6-HT columns and two TSKgel GNH6-HTL columns, each having adiameter of 7.5 mm and a length of 300 mm. The column temperature was140° C. The mobile phase was o-dichlorobenzene (Wako Pure ChemicalIndustries, Ltd.) containing 0.025 wt % of BHT (Takeda ChemicalIndustries, Ltd.) as an antioxidant. The mobile phase was pumped at arate of 1.0 ml/min. The sample concentration was 15 mg/10 ml, and thesample injection amount was 500 μl. A differential refractometer wasused as a detector. For molecular weights Mw<1000 and Mw>4×10⁶,polystyrene standards manufactured by Toso Corporation were used. Formolecular weights 1000≦Mw≦4×10⁶, polystyrene standards available fromPressure Chemical Co. were used. Here, Mw and Mn represent weightaverage molecular weight and number average molecular weight,respectively.

[Melting Point]

The melting point (Tm) of the polymer was determined by differentialscanning calorimetry (DSC). In detail, a polymer sample held at 240° C.for 10 minutes was cooled to 30° C. and held at the temperature for 5minutes, and was thereafter heated at a temperature increasing rate of10° C./min. The melting point was calculated from the peak assigned tocrystal fusion by the temperature increasing.

[Intrinsic Viscosity [η]]

The intrinsic viscosity was measured at 135° C. in decalin and wasexpressed in dl/g.

[Melt Flow Rate (MFR)]

The melt flow rate (MFR) [g/10 min] of the copolymers (A) was determinedin accordance with ASTM D1238 at 230° C. and under a load of 2.16 kg.

The melt flow rate (MFR) [g/10 min] of the copolymers (B) was determinedin accordance with ASTM D1238 at 190° C. and under a load of 2.16 kg.

[Elastic Modulus of Films [Vertical/Horizontal] ]

The elastic modulus of films [vertical (MPa)/horizontal (MPa)] wasdetermined in accordance with ASTM D638.

[Film Impact Strength]

A 100 mm×100 mm film was tested with a film impact tester manufacturedby Toyo Seiki Seisaku-Sho, Ltd. The impact hammer was a sphere with adiameter of 1 inch, and the testing temperature was −10° C. The impactstrength was expressed in J/m.

[Fillability of Melt Bags]

A film 50 μm in thickness was made into a bag 50 cm in length and 30 cmin width. The bag was filled with 2 kg of carbon black, and thefillability was evaluated under the following criteria.

AA: The bag was self-standing with the mouth open.

BB: The bag needed a support of one hand to stand with the mouth open.

CC: The bag bent and the mouth was not open.

[Molten State of Melt Bags]

A film weighing 2 g was added to 100 g of a rubber compound (Mitsui EPTX-4010 manufactured by Mitsui Chemicals, Inc.) and these were kneadedtogether with an 85° C. roll for 5 minutes. The kneaded product wasvisually observed for unmolten film. The molten state was evaluatedbased on the following criteria.

AA: No unmolten film was observed.

BB: Almost no unmolten film was observed.

CC: Unmolten film was observed.

[Storage Stability of Melt Bags]

A film was stored at 40° C. for 6 months, and the storage stability wasevaluated based on the following criteria.

AA: The film remained unchanged.

BB: The film remained almost unchanged.

CC: The film became brittle and collapsed.

Catalyst preparation examples, copolymer production examples andcopolymer properties will be described below.

Catalyst Preparation Example 1 Synthesis of dimethylmethylene(3-tert-butyl-5-methyl-cyclopentadienyl) (fluorenyl) zirconiumdichloride 1) Synthesis of 1-tert-butyl-3-methylcyclopentadiene

In a nitrogen atmosphere, a solution of 43.7 g (0.45 mmol) of3-methylcyclopentenone in 150 ml of dried diethyl ether was addeddropwise to a solution obtained by adding dried diethyl ether (350 ml)to 450 ml (0.90 mol) of a 2.0 mol/L tert-butylmagnesium chloride/diethylether solution. During the dropwise addition, the temperature was keptat 0° C. by ice cooling. The mixture was stirred at room temperature for15 hours. To the reaction solution, a solution of 80.0 g (1.50 mol) ofammonium chloride in 350 ml of water was added dropwise while keepingthe temperature at 0° C. with ice cooling. Water in a volume of 2500 mlwas added to the resultant solution, and the mixture was stirred. Theorganic phase was separated and washed with water. Thereafter, 82 ml ofa 10% aqueous hydrochloric acid solution was added to the organic phasewhile the temperature was kept at 0° C. with ice cooling. The mixturewas stirred at room temperature for 6 hours. The organic phase of theresultant reaction liquid was separated, then washed with water, asaturated aqueous sodium hydrogen carbonate solution, water and asaturated saline solution, and dried over anhydrous magnesium sulfate.The desiccant was filtered off, and the solvent was distilled away fromthe filtrate, resulting in a liquid. The liquid was distilled underreduced pressure (45-47° C./10 mm Hg) to give 14.6 g of a light yellowliquid. The analytical data are given below.

¹H-NMR (270 MHz, in CDCl₃, TMS standard) δ 6.31+6.13+5.94+5.87 (s+s+t+d,2H), 3.04+2.95 (s+s, 2H), 2.17+2.09 (s+s, 3H), 1.27 (d, 9H)

2) Synthesis of 3-tert-butyl-1,6,6-trimethylfulvene

In a nitrogen atmosphere, 55.2 g (950.4 mmol) of dried acetone was addeddropwise to a solution of 13.0 g (95.6 mmol) of1-tert-butyl-3-methylcyclopentadiene in 130 ml of dried methanol, andsubsequently 68.0 g (956.1 mmol) of pyrrolidine was added theretodropwise. During the dropwise addition, the temperature was kept at 0°C. by ice cooling. The mixture was stirred at room temperature for 4days. The resultant reaction liquid was diluted with 400 ml of diethylether, and 400 ml of water was added. The organic phase was separated,then washed with a 0.5 N aqueous hydrochloric acid solution (150 ml×4),water (200 ml×3) and a saturated saline solution (150 ml), and driedover anhydrous magnesium sulfate. The desiccant was filtered off, andthe solvent was distilled away from the filtrate, resulting in a liquid.The liquid was distilled under reduced pressure (70-80° C./0.1 mm Hg) togive 10.5 g of a yellow liquid. The analytical data are given below.

¹H-NMR (270 MHz, in CDCl₃, TMS standard) δ6.23 (s, 1H), 6.05 (d, 1H),2.23 (s, 3H), 2.17 (d, 6H), 1.17 (s, 9H)

3) Synthesis of 2-(3-tert-butyl-5-methylcyclopentadienyl)-2-fluorenylpropane

In a nitrogen atmosphere, 40 ml (61.6 mmol) of a hexane solution ofn-butyllithium was added dropwise to a solution of 10.1 g (60.8 mmol) offluorene in 300 ml of THF with ice cooling. The mixture was stirred atroom temperature for 5 hours (resulting in a dark brown solution). Thesolution was ice cooled again, and a solution of 11.7 g (66.5 mmol) of3-tert-butyl-1,6,6-trimethylfulvene in 300 ml of THF was added theretodropwise in a nitrogen atmosphere. The mixture was stirred at roomtemperature for 14 hours. The resultant brown solution was ice cooled,and 200 ml of water was added. The organic phase was extracted withdiethyl ether, then separated, and dried over magnesium sulfate. Thedesiccant was filtered off, and the solvent was removed from thefiltrate under reduced pressure, resulting in an orange-brown oil. Theoil was purified by silica gel column chromatography (developingsolvent: hexane) to give 3.8 g of a yellow oil. The analytical data aregiven below.

¹H-NMR (270 MHz, in CDCl₃, TMS standard) δ7.70 (d, 4H), 7.34-7.26 (m,6H), 7.18-7.11 (m, 6H), 6.17 (s, 1H), 6.01 (s, 1H), 4.42 (s, 1H), 4.27(s, 1H), 3.01 (s, 2H), 2.87 (s, 2H), 2.17 (s, 3H), 1.99 (s, 3H), 2.10(s, 9H), 1.99 (s, 9H), 1.10 (s, 6H), 1.07 (s, 6H)

4) Synthesis ofdimethylmethylene(3-tert-butyl-5-methylcyclopentadienyl)fluorenylzirconiumdichloride

In a nitrogen atmosphere, 5.0 ml (7.7 mmol) of a hexane solution ofn-butyllithium was added dropwise to a solution of 1.14 g (3.3 mmol) of2-(3-tert-butyl-5-methylcyclopentadienyl)-2-fluorenylpropane in 25 ml ofdiethyl ether with ice cooling. The mixture was stirred at roomtemperature for 14 hours to give a pink slurry. Zirconium tetrachlorideweighing 0.77 g (3.3 mmol) was added to the slurry at −78° C. Themixture was stirred at −78° C. for several hours and at room temperaturefor 65 hours. The resultant dark brown slurry was filtered. The residuewas washed with 10 ml of diethyl ether, and the filtrate was extractedwith dichloromethane to give a red solution. The solvent of the solutionwas distilled away under reduced pressure to give 0.53 g of a red orangesolid. The analytical data are given below.

¹H-NMR (270 MHz, in CDCl₃, TMS standard) δ8.11-8.02 (m, 3H), 7.82 (d,1H), 7.56-7.45 (m, 2H), 7.23-7.17 (m, 2H), 6.08 (d, 1H), 5.72 (d, 1H),2.59 (s, 3H), 2.41 (s, 3H), 2.30 (s, 3H), 1.08 (s, 9H) FD-MS: m/z=500,502, 504 (M⁺)

Production Example 1 PBR-1 (Preparation of Propylene/1-Butene Copolymer(A) with Metallocene Catalyst)

A 2000 ml polymerizer that had been thoroughly purged with nitrogen wascharged with 866 ml of dried hexane, 90 g of 1-butene and 1.0 mmol oftriisobutylaluminum at normal temperature. The temperature inside thepolymerizer was increased to 65° C., and the polymerizer was pressurizedto 0.7 MPa with propylene. Subsequently, there was added to thepolymerizer a toluene solution in which 0.002 mmol ofdimethylmethylene(3-tert-butyl-5-methylcyclopentadienyl)fluorenylzirconium dichloride and 0.6 mmol in terms of aluminum ofmethylaluminoxane (manufactured by Tosoh Finechem Corporation) were incontact with each other. Polymerization was carried out for 30 minuteswhile keeping the internal temperature at 65° C. and the propylenepressure at 0.7 MPa, and was terminated by the addition of 20 ml ofmethanol. The polymerizer was depressurized, and the polymer wasprecipitated by adding the polymerization solution to 2 L of methanoland was dried under vacuum at 130° C. for 12 hours. The polymer thusobtained weighed 12.5 g and had an intrinsic viscosity [η] of 1.63 dl/gand an mm fraction of 90%. The polymer also had a butene content of 27.9mol %, a melting point (Tm) of 74.7° C., an MFR (230° C., 2.16 kg load)of 7.0 g/10 min, and Mw/Mn of 2.1.

With M being 27.9 in the equation of Requirement (5):−2.6M+130≦Tm≦−2.3M+155, the equation became 57.46≦Tm≦90.83. The meltingpoint Tm: 74.7° C. satisfied this relation.

The above sample preparation was scaled up, and 10 kg of a polymer wasobtained. The polymer had a butene content of 27.8 mol %, an intrinsicviscosity [η] of 1.63 dl/g, an mm fraction of 90%, a melting point (Tm)of 75° C., an MFR (230° C., 2.16 kg load) of 7.0 g/10 min, and Mw/Mn of2.1.

Production Example 2 PBR-2 (Preparation of Propylene/1-Butene Copolymer(A) with Metallocene Catalyst)

Polymerization was carried out in the same manner as in ProductionExample 1, except that the amounts of hexane and 1-butene were 850 mland 90 g, respectively, and that the temperature inside the polymerizerwas changed to 60° C. The polymer obtained weighed 19.5 g. The polymerhad a butene content of 16.9 mol %, a melting point (Tm) of 86.3° C., anMFR (230° C., 2.16 kg load) of 6.05 g/10 min, Mw/Mn of 2.11, anintrinsic viscosity [η] of 1.58 dl/g, and an mm fraction of 91%.

With M being 18.9 in the equation of Requirement (5):−2.6M+130≦Tm≦−2.3M+155, the equation became 80.86≦Tm≦111.53. The meltingpoint Tm: 86.3° C. satisfied this relation.

The above sample preparation was scaled up, and 10 kg of a polymer wasobtained. The polymer had a butene content of 16.8 mol %, an intrinsicviscosity [η] of 1.58 dl/g, an mm fraction of 91%, a melting point (Tm)of 86° C., an MFR (230° C., 2.16 kg load) of 6.1 g/10 min, and Mw/Mn of2.1.

Production Example 3 Ethylene/1-Butene Copolymer (EBR-1) (B)

A 2000 ml polymerizer that had been thoroughly purged with nitrogen wascharged with 890 ml of dried hexane, 65 g of 1-butene and 0.2 mmol oftriisobutylaluminum at normal temperature. The temperature inside thepolymerizer was increased to 90° C., and 150 N ml of hydrogen was added.The polymerizer was pressurized to 0.8 MPaG with ethylene.Polymerization was performed in the presence of 0.0005 mmol of[dimethyl(t-butylamido)(tetramethyl-η-5-cyclopentadienyl)silane]titanium dichloride and 0.0025mmol of triphenylcarbenium (tetrakispentafluorophenyl)borate for 15minutes while keeping the internal temperature at 90° C. and theethylene pressure at 0.8 MPaG. The polymerization was terminated by theaddition of 20 ml of methanol. The polymerizer was depressurized, andthe polymer was precipitated by adding the polymerization solution to 2L of methanol and was dried under vacuum at 130° C. for 12 hours. Thepolymer thus obtained weighed 69.5 g and had an intrinsic viscosity [η]of 1.50 dl/g. The polymer also had a butene content of 11.2 mol %, amelting point (Tm) of 67° C., an MFR (190° C., 2.16 kg load) of 3.6 g/10min, and Mw/Mn of 2.1.

The above sample preparation was scaled up, and 10 kg of a polymer wasobtained. The polymer had a butene content of 11.2 mol %, an intrinsicviscosity [η] of 1.50 dl/g, a melting point (Tm) of 67° C., an MFR (190°C., 2.16 kg load) of 3.6 g/10 min, and Mw/Mn of 2.1.

Production Example 4 Ethylene/1-Butene Copolymer (EBR-2)

A 2000 ml polymerizer that had been thoroughly purged with nitrogen wascharged with 950 ml of dried hexane, 32 g of 1-butene and 0.2 mmol oftriisobutylaluminum at normal temperature. The temperature inside thepolymerizer was increased to 90° C., and 150 N ml of hydrogen was added.The polymerizer was pressurized to 0.8 MPaG with ethylene.

Polymerization was performed in the presence of 0.0005 mmol of[dimethyl(t-butylamido)(tetramethyl-η-5-cyclopentadienyl)silane]titanium dichloride and 0.0025mmol of triphenylcarbenium (tetrakispentafluorophenyl)borate for 15minutes while keeping the internal temperature at 90° C. and theethylene pressure at 0.8 MPaG. The polymerization was terminated by theaddition of 20 ml of methanol. The polymerizer was depressurized, andthe polymer was precipitated by adding the polymerization solution to 2L of methanol and was dried under vacuum at 130° C. for 12 hours. Thepolymer thus obtained weighed 75.3 g. The polymer had a butene contentof 5.2 mol %, a melting point of 96° C., an intrinsic viscosity [η] of1.6 dl/g, and Mw/Mn of 2.0.

[Linear Low-Density Polyethylene (LLDPE)]

EVOLUE SP2520 (manufactured by Prime Polymer Co., Ltd., MFR=1.5 g/10 min(190° C., 2.16 kg), Tm=121° C.) was used as a linear low-densitypolyethylene (LLDPE).

[Ethylene Vinyl Acetate Copolymer (EVA)]

EVAFLEX EV460 (manufactured by DU PONT-MITSUI POLYCHEMICALS CO., LTD.,MFR=2.5 g/10 min (190° C., 2.16 kg), Tm=84° C.) was used as an ethylenevinyl acetate copolymer (EVA).

[Polybutadiene]

Polybutadiene RB830 (manufactured by JSR Corporation, MFR=3 g/10 min(150° C., 2.16 kg), Tm=105° C.) was used.

[Ethylene/Octene Copolymer (EOR)]

TAFMER H-430 (manufactured by Mitsui Chemicals, Inc., melting point: 66°C., Mw/Mn: 2.1, MFR (190° C., 2.16 kg): 4 g/10 min) was used asethylene/octene copolymer.

[Propylene/1-Butene Copolymer (PBR-3)]

TAFMER XR110T (manufactured by Mitsui Chemicals, Inc., melting point:110° C., Mw/Mn: 4.2, MFR (230° C., 2.16 kg): 6 g/10 min) was used aspropylene/1-butene copolymer (PBR-3).

Example 1

A blend consisting of 30 parts by weight of the propylene/1-butenecopolymer (PBR-1) from Production Example 1 and 70 parts by weight ofthe ethylene/1-butene copolymer (EBR-1) (B) was formed into asingle-layer film in a thickness of 150 μm by a blown-film extrusionmethod under the following forming and extrusion conditions. The filmand a melt bag obtained therefrom (produced as described hereinabove)were evaluated for properties. The results are set forth in Table 2.

[Blown-Film Extrusion Conditions]

Blown-film extrusion apparatus: extruder (100 mm diameter) manufacturedby Modern Machinery

Screw: L/D=28

Compression ratio: 2.0

Dice diameter: 200 mm

Lip width: 1.5 mm

Extruder preset temperatures: cylinder 150° C., dice 135° C.

Swell ratio: 1.5

Take-up speed: 10 m/min

[Extrusion Conditions]

Resin pressure P: 150 kg/cm³

Resin output: 100 kg/hr

Resin temperature T: 140° C.

Examples 2 to 5

Materials were dry blended in the amounts shown in Table 2 to give resincompositions, and the compositions were formed into single-layer filmsin a thickness of 150 μm under the same conditions as in Example 1. Thefilms and melt bags obtained therefrom (produced as describedhereinabove) were evaluated for properties similarly to Example 1. Theresults are set forth in Table 2.

Comparative Examples 1 to 7

Materials were dry blended in the amounts shown in Table 3 to give resincompositions, and the compositions were formed into single-layer filmsin a thickness of 150 μm under the same conditions as in Example 1. Thefilms and melt bags obtained therefrom (produced as describedhereinabove) were evaluated for properties similarly to Example 1. Theresults are set forth in Table 3.

TABLE 2 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Resin PBR-1 wt % 30 50 70 — 50composition PBR-2 wt % — — — 50 — EBR-1 wt % 70 50 30 50 — EOR wt % — —— — 50 Film Film thickness μm 150 150 150 150 150 properties Meltingpoint ° C. 72 73 75 68 73 86 Elastic modulus MPa/MPa 90/70 140/120200/180 160/140 130/120 (vertical/horizontal) Film impact J/m 10 13 N.B.20 15 Melt bag Fillability BB BB AA AA BB properties Molten state AA AAAA BB AA Storage stability AA AA AA AA AA *N.B.: Not Break (The film wasnot broken in the evaluation.)

TABLE 3 Comp. Comp. Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex. 3 Ex.4 Ex. 5 Ex. 6 Ex. 7 Resin PBR-1 wt % — — — — 30 50 — composition PBR-2wt % — — — — — — — PBR-3 wt % — — — — — — 50 EBR-1 wt % 100 — — — — — 50EBR-2 wt % — — — — — 50 — LLDPE wt % — 100 — 45 70 — — EVA wt % — — — 55— — — Polybutadiene wt % — — 100 — — — — Film Film thickness μm 150 150150 150 150 150 150 properties Melting point ° C. 67 121 105 87 75 75 67113 113 96 110 Elastic modulus MPa/MPa 30/30 180/180 130/150 150/150190/170 130/120 170/150 (vertical/horizontal) Film impact J/m 6 18 16 1810 15 13 Melt bag Fillability CC AA BB BB BB BB AA properties Moltenstate AA CC AA CC CC CC CC Storage stability AA AA CC AA AA AA AA

1. A melt bag which is formed using a resin composition, wherein theresin composition comprises: a propylene/1-butene copolymer (A) and anethylene/1-butene copolymer (B), wherein the weight ratio of thesecopolymers (A)/(B) is in the range of 90/10 to 70/30, wherein thepropylene/1-butene copolymer (A) has (1) a melting point (Tm) of 40 to85° C. as measured by differential scanning calorimetry (DSC) andcontains (2) structural units derived from propylene in an amount of 60to 80 mol % and structural units derived from 1-butene in an amount of20 to 40 mol %, wherein the ethylene/1-butene copolymer (B) has (1) amelting point (Tm) of 40 to 85° C. as measured by differential scanningcalorimetry (DSC) and contains (2) structural units derived fromethylene in an amount of 50 to 95 mol % and structural units derivedfrom 1-butene in an amount of 5 to 50 mol %.
 2. The melt bag accordingto claim 1, wherein the propylene/1-butene copolymer (A) has: (3) amolecular weight distribution (Mw/Mn) of not more than 3.0 as measuredby gel permeation chromatography (GPC).
 3. The melt bag according toclaim 1, wherein the ethylene/1-butene copolymer (B) has: (3) amolecular weight distribution (Mw/Mn) of not more than 3.0 as measuredby gel permeation chromatography (GPC).
 4. The melt bag according toclaim 1, wherein the propylene/1-butene copolymer (A) has: (6) a triadtacticity (mm fraction) of not less than 90% as determined using¹³C-NMR.
 5. The melt bag according to claim 1, wherein theethylene/1-butene copolymer (B) has: (4) the intrinsic viscosity [η]within the range of 0.1 to 12 dl/g as measured at 135° C. in decalin and(5) a melt flow rate (MFR) within a range of 0.2 to 35 g/10 min asdetermined at 190° C. under a load of 2.16 kg in accordance with ASTMD1238.
 6. The melt bag according to claim 1, wherein thepropylene/1-butene copolymer (A) has: (4) the intrinsic viscosity [η]within the range of 0.1 to 12 dl/g as measured at 135° C. in decalin,(5) the melting point (Tm) of 40 to 85° C. as measured by differentialscanning calorimetry (DSC) and the melting point (Tm) and the content(M) (mol %) of structural unit derived from 1-butene satisfying thefollowing relation:−2.6M+130≦Tm≦−2.3M+155 and (7) a melt flow rate (MFR) within a range of1 to 10 g/10 min as determined at 230° C. under a load of 2.16 kg inaccordance with ASTM D1238.
 7. A package which includes the melt bagdescribed in claim 1.